/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
class MidiInput::Pimpl
{
public:
    static Array<Pimpl*> midiInputs;

    Pimpl (const String& port, MidiInput* input, MidiInputCallback* callback)
        : midiInput (input), midiPort (port), midiCallback (callback)
    {
        jassert (midiCallback != nullptr);
        midiInputs.add (this);

        buffer.resize (32);
    }

    ~Pimpl()
    {
        stop();
        midiInputs.removeAllInstancesOf (this);
    }

    void start()
    {
        midi.readFrom (midiPort.toRawUTF8());
    }

    void stop()
    {
        midi.enableParser (false);
    }

    void poll()
    {
        size_t receivedBytes = 0;

        for (;;)
        {
            auto data = midi.getInput();

            if (data < 0)
                break;

            buffer[receivedBytes] = (uint8) data;
            receivedBytes++;

            if (receivedBytes == buffer.size())
            {
                pushMidiData (static_cast<int> (receivedBytes));
                receivedBytes = 0;
            }
        }

        if (receivedBytes > 0)
            pushMidiData ((int) receivedBytes);
    }

    static Array<MidiDeviceInfo> getDevices (bool input)
    {
        Array<MidiDeviceInfo> devices;

        for (auto& card : findAllALSACardIDs())
            findMidiDevices (devices, input, card);

        return devices;
    }

    void pushMidiMessage (juce::MidiMessage& message)
    {
        concatenator.pushMidiData (message.getRawData(), message.getRawDataSize(), Time::getMillisecondCounter() * 0.001, midiInput, *midiCallback);
    }

private:
    void pushMidiData (int length)
    {
        concatenator.pushMidiData (buffer.data(), length, Time::getMillisecondCounter() * 0.001, midiInput, *midiCallback);
    }

    std::vector<uint8> buffer;

    static Array<int> findAllALSACardIDs()
    {
        Array<int> cards;
        int card = -1;

        for (;;)
        {
            auto status = snd_card_next (&card);

            if (status != 0 || card < 0)
                break;

            cards.add (card);
        }

        return cards;
    }

    // Adds all midi devices to the devices array of the given input/output type on the given card
    static void findMidiDevices (Array<MidiDeviceInfo>& devices, bool input, int cardNum)
    {
        snd_ctl_t* ctl = nullptr;
        auto status = snd_ctl_open (&ctl, ("hw:" + String (cardNum)).toRawUTF8(), 0);

        if (status < 0)
            return;

        int device = -1;

        for (;;)
        {
            status = snd_ctl_rawmidi_next_device (ctl, &device);

            if (status < 0 || device < 0)
                break;

            snd_rawmidi_info_t* info;
            snd_rawmidi_info_alloca (&info);

            snd_rawmidi_info_set_device (info, (unsigned int) device);
            snd_rawmidi_info_set_stream (info, input ? SND_RAWMIDI_STREAM_INPUT
                                                     : SND_RAWMIDI_STREAM_OUTPUT);

            snd_ctl_rawmidi_info (ctl, info);

            auto subCount = snd_rawmidi_info_get_subdevices_count (info);

            for (size_t sub = 0; sub < subCount; ++sub)
            {
                snd_rawmidi_info_set_subdevice (info, sub);

                status = snd_ctl_rawmidi_info (ctl, info);

                if (status == 0)
                {
                    String deviceName ("hw:" + String (cardNum) + "," + String (device) + "," + String (sub));
                    devices.add (MidiDeviceInfo (deviceName, deviceName));
                }
            }
        }

        snd_ctl_close (ctl);
    }

    MidiInput* const midiInput;
    String midiPort;
    MidiInputCallback* const midiCallback;

    Midi midi;
    MidiDataConcatenator concatenator { 512 };

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Pimpl)
};

Array<MidiInput::Pimpl*> MidiInput::Pimpl::midiInputs;


//==============================================================================
class BelaAudioIODevice final : public AudioIODevice
{
public:
    BelaAudioIODevice()  : AudioIODevice (BelaAudioIODevice::belaTypeName,
                                          BelaAudioIODevice::belaTypeName)
    {
        Bela_defaultSettings (&defaultSettings);
    }

    ~BelaAudioIODevice()
    {
        close();
    }

    //==============================================================================
    StringArray getOutputChannelNames() override
    {
        StringArray result;

        for (int i = 1; i <= actualNumberOfOutputs; i++)
            result.add ("Out #" + std::to_string (i));

        return result;
    }

    StringArray getInputChannelNames() override
    {
        StringArray result;

        for (int i = 1; i <= actualNumberOfInputs; i++)
            result.add ("In #" + std::to_string (i));

        return result;
    }

    Array<double> getAvailableSampleRates() override       { return { 44100.0 }; }
    Array<int> getAvailableBufferSizes() override          { /* TODO: */ return { getDefaultBufferSize() }; }
    int getDefaultBufferSize() override                    { return defaultSettings.periodSize; }

    //==============================================================================
    String open (const BigInteger& inputChannels,
                 const BigInteger& outputChannels,
                 double sampleRate,
                 int bufferSizeSamples) override
    {
        if (sampleRate != 44100.0 && sampleRate != 0.0)
        {
            lastError = "Bela audio outputs only support 44.1 kHz sample rate";
            return lastError;
        }

        settings = defaultSettings;

        auto numIns = getNumContiguousSetBits (inputChannels);
        auto numOuts = getNumContiguousSetBits (outputChannels);

        // Input and Output channels are numbered as follows
        //
        // 0  .. 1  - audio
        // 2  .. 9  - analog

        if (numIns > 2 || numOuts > 2)
        {
            settings.useAnalog            = true;
            settings.numAnalogInChannels  = std::max (numIns - 2, 8);
            settings.numAnalogOutChannels = std::max (numOuts - 2, 8);
            settings.uniformSampleRate    = true;
        }

        settings.numAudioInChannels   = std::max (numIns, 2);
        settings.numAudioOutChannels  = std::max (numOuts, 2);

        settings.detectUnderruns      = 1;
        settings.setup                = setupCallback;
        settings.render               = renderCallback;
        settings.cleanup              = cleanupCallback;
        settings.interleave           = 0;

        if (bufferSizeSamples > 0)
            settings.periodSize = bufferSizeSamples;

        isBelaOpen = false;
        isRunning  = false;
        callback   = nullptr;
        underruns  = 0;

        if (Bela_initAudio (&settings, this) != 0 || ! isBelaOpen)
        {
            lastError = "Bela_initAutio failed";
            return lastError;
        }

        actualNumberOfInputs  = jmin (numIns, actualNumberOfInputs);
        actualNumberOfOutputs = jmin (numOuts, actualNumberOfOutputs);

        channelInBuffer.calloc (actualNumberOfInputs);
        channelOutBuffer.calloc (actualNumberOfOutputs);

        return {};
    }

    void close() override
    {
        stop();

        if (isBelaOpen)
        {
            Bela_cleanupAudio();

            isBelaOpen = false;
            callback = nullptr;
            underruns = 0;

            actualBufferSize = 0;
            actualNumberOfInputs = 0;
            actualNumberOfOutputs = 0;

            channelInBuffer.free();
            channelOutBuffer.free();
        }
    }

    bool isOpen() override   { return isBelaOpen; }

    void start (AudioIODeviceCallback* newCallback) override
    {
        if (! isBelaOpen)
            return;

        if (isRunning)
        {
            if (newCallback != callback)
            {
                if (newCallback != nullptr)
                    newCallback->audioDeviceAboutToStart (this);

                {
                    ScopedLock lock (callbackLock);
                    std::swap (callback, newCallback);
                }

                if (newCallback != nullptr)
                    newCallback->audioDeviceStopped();
            }
        }
        else
        {
            callback = newCallback;
            isRunning = (Bela_startAudio() == 0);

            if (callback != nullptr)
            {
                if (isRunning)
                {
                    callback->audioDeviceAboutToStart (this);
                }
                else
                {
                    lastError = "Bela_StartAudio failed";
                    callback->audioDeviceError (lastError);
                }
            }
        }
    }

    void stop() override
    {
        AudioIODeviceCallback* oldCallback = nullptr;

        if (callback != nullptr)
        {
            ScopedLock lock (callbackLock);
            std::swap (callback, oldCallback);
        }

        isRunning = false;
        Bela_stopAudio();

        if (oldCallback != nullptr)
            oldCallback->audioDeviceStopped();
    }

    bool isPlaying() override         { return isRunning; }
    String getLastError() override    { return lastError; }

    //==============================================================================
    int getCurrentBufferSizeSamples() override            { return (int) actualBufferSize; }
    double getCurrentSampleRate() override                { return 44100.0; }
    int getCurrentBitDepth() override                     { return 16; }
    BigInteger getActiveOutputChannels() const override   { BigInteger b; b.setRange (0, actualNumberOfOutputs, true); return b; }
    BigInteger getActiveInputChannels() const override    { BigInteger b; b.setRange (0, actualNumberOfInputs, true);  return b; }
    int getOutputLatencyInSamples() override              { /* TODO */ return 0; }
    int getInputLatencyInSamples() override               { /* TODO */ return 0; }
    int getXRunCount() const noexcept override            { return underruns; }

    //==============================================================================
    static const char* const belaTypeName;

private:

    //==============================================================================
    bool setup (BelaContext& context)
    {
        actualBufferSize      = context.audioFrames;
        actualNumberOfInputs  = (int) (context.audioInChannels + context.analogInChannels);
        actualNumberOfOutputs = (int) (context.audioOutChannels + context.analogOutChannels);
        isBelaOpen = true;
        firstCallback = true;

        ScopedLock lock (callbackLock);

        if (callback != nullptr)
            callback->audioDeviceAboutToStart (this);

        return true;
    }

    void render (BelaContext& context)
    {
        // check for xruns
        calculateXruns (context.audioFramesElapsed, context.audioFrames);

        ScopedLock lock (callbackLock);

        // Check for and process and midi
        for (auto midiInput : MidiInput::Pimpl::midiInputs)
            midiInput->poll();

        if (callback != nullptr)
        {
            jassert (context.audioFrames <= actualBufferSize);
            jassert ((context.flags & BELA_FLAG_INTERLEAVED) == 0);

            using Frames = decltype (context.audioFrames);

            // Setup channelInBuffers
            for (int ch = 0; ch < actualNumberOfInputs; ++ch)
            {
                if (ch < analogChannelStart)
                    channelInBuffer[ch] = &context.audioIn[(Frames) ch * context.audioFrames];
                else
                    channelInBuffer[ch] = &context.analogIn[(Frames) (ch - analogChannelStart) * context.analogFrames];
            }

            // Setup channelOutBuffers
            for (int ch = 0; ch < actualNumberOfOutputs; ++ch)
            {
                if (ch < analogChannelStart)
                    channelOutBuffer[ch] = &context.audioOut[(Frames) ch * context.audioFrames];
                else
                    channelOutBuffer[ch] = &context.analogOut[(Frames) (ch - analogChannelStart) * context.audioFrames];
            }

            callback->audioDeviceIOCallbackWithContext (channelInBuffer.getData(),
                                                        actualNumberOfInputs,
                                                        channelOutBuffer.getData(),
                                                        actualNumberOfOutputs,
                                                        (int) context.audioFrames,
                                                        {});
        }
    }

    void cleanup (BelaContext&)
    {
        ScopedLock lock (callbackLock);

        if (callback != nullptr)
            callback->audioDeviceStopped();
    }

    const int analogChannelStart  = 2;

    //==============================================================================
    uint64_t expectedElapsedAudioSamples = 0;
    int underruns = 0;
    bool firstCallback = false;

    void calculateXruns (uint64_t audioFramesElapsed, uint32_t numSamples)
    {
        if (audioFramesElapsed > expectedElapsedAudioSamples && ! firstCallback)
            ++underruns;

        firstCallback = false;
        expectedElapsedAudioSamples = audioFramesElapsed + numSamples;
    }

    //==============================================================================
    static int getNumContiguousSetBits (const BigInteger& value) noexcept
    {
        int bit = 0;

        while (value[bit])
            ++bit;

        return bit;
    }

    //==============================================================================
    static bool setupCallback   (BelaContext* context, void* userData) noexcept    { return static_cast<BelaAudioIODevice*> (userData)->setup (*context); }
    static void renderCallback  (BelaContext* context, void* userData) noexcept    { static_cast<BelaAudioIODevice*> (userData)->render (*context); }
    static void cleanupCallback (BelaContext* context, void* userData) noexcept    { static_cast<BelaAudioIODevice*> (userData)->cleanup (*context); }

    //==============================================================================
    BelaInitSettings defaultSettings, settings;
    bool isBelaOpen = false, isRunning = false;

    CriticalSection callbackLock;
    AudioIODeviceCallback* callback = nullptr;

    String lastError;
    uint32_t actualBufferSize = 0;
    int actualNumberOfInputs = 0, actualNumberOfOutputs = 0;

    HeapBlock<const float*> channelInBuffer;
    HeapBlock<float*> channelOutBuffer;

    bool includeAnalogSupport;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BelaAudioIODevice)
};

const char* const BelaAudioIODevice::belaTypeName = "Bela Analog";

//==============================================================================
struct BelaAudioIODeviceType final : public AudioIODeviceType
{
    BelaAudioIODeviceType() : AudioIODeviceType ("Bela") {}

    StringArray getDeviceNames (bool) const override                       { return StringArray (BelaAudioIODevice::belaTypeName); }
    void scanForDevices() override                                         {}
    int getDefaultDeviceIndex (bool) const override                        { return 0; }
    int getIndexOfDevice (AudioIODevice* device, bool) const override      { return device != nullptr ? 0 : -1; }
    bool hasSeparateInputsAndOutputs() const override                      { return false; }

    AudioIODevice* createDevice (const String& outputName, const String& inputName) override
    {
        // TODO: switching whether to support analog/digital with possible multiple Bela device types?
        if (outputName == BelaAudioIODevice::belaTypeName || inputName == BelaAudioIODevice::belaTypeName)
            return new BelaAudioIODevice();

        return nullptr;
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BelaAudioIODeviceType)
};

//==============================================================================
MidiInput::MidiInput (const String& deviceName, const String& deviceID)
    : deviceInfo (deviceName, deviceID)
{
}

MidiInput::~MidiInput() = default;
void MidiInput::start()   { internal->start(); }
void MidiInput::stop()    { internal->stop(); }

Array<MidiDeviceInfo> MidiInput::getAvailableDevices()
{
    return Pimpl::getDevices (true);
}

MidiDeviceInfo MidiInput::getDefaultDevice()
{
    return getAvailableDevices().getFirst();
}

std::unique_ptr<MidiInput> MidiInput::openDevice (const String& deviceIdentifier, MidiInputCallback* callback)
{
    if (deviceIdentifier.isEmpty())
        return {};

    std::unique_ptr<MidiInput> midiInput (new MidiInput (deviceIdentifier, deviceIdentifier));
    midiInput->internal = std::make_unique<Pimpl> (deviceIdentifier, midiInput.get(), callback);

    return midiInput;
}

std::unique_ptr<MidiInput> MidiInput::createNewDevice (const String&, MidiInputCallback*)
{
    // N/A on Bela
    jassertfalse;
    return {};
}

StringArray MidiInput::getDevices()
{
    StringArray deviceNames;

    for (auto& d : getAvailableDevices())
        deviceNames.add (d.name);

    return deviceNames;
}

int MidiInput::getDefaultDeviceIndex()
{
    return 0;
}

std::unique_ptr<MidiInput> MidiInput::openDevice (int index, MidiInputCallback* callback)
{
    return openDevice (getAvailableDevices()[index].identifier, callback);
}

//==============================================================================
// TODO: Add Bela MidiOutput support
class MidiOutput::Pimpl {};
MidiOutput::~MidiOutput() = default;
void MidiOutput::sendMessageNow (const MidiMessage&)                     {}
Array<MidiDeviceInfo> MidiOutput::getAvailableDevices()                  { return {}; }
MidiDeviceInfo MidiOutput::getDefaultDevice()                            { return {}; }
std::unique_ptr<MidiOutput> MidiOutput::openDevice (const String&)       { return {}; }
std::unique_ptr<MidiOutput> MidiOutput::createNewDevice (const String&)  { return {}; }
StringArray MidiOutput::getDevices()                                     { return {}; }
int MidiOutput::getDefaultDeviceIndex()                                  { return 0;}
std::unique_ptr<MidiOutput> MidiOutput::openDevice (int)                 { return {}; }

} // namespace juce
